R.I. Gen. Laws § 40.1-23-2: Who may serve.

(a) A parental successor may be an individual, whether related or not to the person who has been determined to be a person with developmental disabilities under the regulations of the director of the department of behavioral healthcare, developmental disabilities and hospitals; a bank with a trust department, acting through its trust department; a church, acting through the incumbent of a position to be indicated in the instrument designating or the order appointing the parental successor; or an organization concerned with the needs of individuals with developmental disabilities.

(b) A minor may be named or appointed as a parental successor, but he or she may actually serve only after reaching the age of eighteen (18) years.